ref: 2ebdfd56bb69cc74b1c64c727c8cb1201fec4653
dir: /src/sf.c/
/*
* July 5, 1991
* Copyright 1991 Lance Norskog And Sundry Contributors
* This source code is freely redistributable and may be used for
* any purpose. This copyright notice must be maintained.
* Lance Norskog And Sundry Contributors are not responsible for
* the consequences of using this software.
*/
/*
* Sound Tools IRCAM SoundFile format handler.
*
* Derived from: Sound Tools skeleton handler file.
*/
#include "st_i.h"
#include "sfircam.h"
#include <string.h>
#include <stdlib.h>
/* Private data for SF file */
typedef struct sfstuff {
struct sfinfo info;
/* needed for seek */
st_size_t dataStart;
} *sf_t;
/*
* Read the codes from the sound file, allocate space for the comment and
* assign its pointer to the comment field in ft.
*/
static void readcodes(ft_t ft, SFHEADER *sfhead)
{
char *commentbuf = NULL, *sfcharp, *newline;
short bsize, finished = 0;
SFCODE *sfcodep;
sfcodep = (SFCODE *) &sfcodes(sfhead);
do {
sfcharp = (char *) sfcodep + sizeof(SFCODE);
if (ft->info.swap) {
sfcodep->bsize = st_swapdw(sfcodep->bsize);
sfcodep->code = st_swapdw(sfcodep->code);
}
bsize = sfcodep->bsize - sizeof(SFCODE);
switch(sfcodep->code) {
case SF_END:
finished = 1;
break;
case SF_COMMENT:
if((commentbuf = (char *) malloc(bsize + 1)) != NULL) {
memcpy(commentbuf, sfcharp, bsize);
st_report("IRCAM comment: %s", sfcharp);
commentbuf[bsize] = '\0';
if((newline = strchr(commentbuf, '\n')) != NULL)
*newline = '\0';
}
break;
}
sfcodep = (SFCODE *) (sfcharp + bsize);
} while(!finished);
if(commentbuf != NULL) /* handles out of memory condition as well */
ft->comment = commentbuf;
}
static int st_sfseek(ft_t ft, st_size_t offset)
{
st_size_t new_offset, channel_block, alignment;
sf_t sf = (sf_t ) ft->priv;
new_offset = offset * ft->info.size;
/* Make sure request aligns to a channel block (ie left+right) */
channel_block = ft->info.channels * ft->info.size;
alignment = new_offset % channel_block;
/* Most common mistaken is to compute something like
* "skip everthing upto and including this sample" so
* advance to next sample block in this case.
*/
if (alignment != 0)
new_offset += (channel_block - alignment);
new_offset += sf->dataStart;
return st_seeki(ft, new_offset, SEEK_SET);
}
/*
* Do anything required before you start reading samples.
* Read file header.
* Find out sampling rate,
* size and encoding of samples,
* mono/stereo/quad.
*/
static int st_sfstartread(ft_t ft)
{
sf_t sf = (sf_t) ft->priv;
SFHEADER sfhead;
int rc;
int samplesize = 0;
if (st_readbuf(ft, &sfhead, 1, sizeof(sfhead)) != sizeof(sfhead))
{
st_fail("unexpected EOF in SF header");
return(ST_EOF);
}
memcpy(&sf->info, &sfhead.sfinfo, sizeof(struct sfinfo));
if (ft->info.swap) {
sf->info.sf_srate = st_swapf(sf->info.sf_srate);
sf->info.sf_packmode = st_swapdw(sf->info.sf_packmode);
sf->info.sf_chans = st_swapdw(sf->info.sf_chans);
}
if ((sfmagic1(&sfhead) != SF_MAGIC1) ||
(sfmagic2(&sfhead) != SF_MAGIC2))
st_fail(
"SF %s file: can't read, it is byte-swapped or it is not an IRCAM SoundFile",
ft->filename);
/*
* If your format specifies or your file header contains
* any of the following information.
*/
ft->info.rate = sf->info.sf_srate;
switch(sf->info.sf_packmode) {
case SF_SHORT:
ft->info.size = ST_SIZE_WORD;
ft->info.encoding = ST_ENCODING_SIGN2;
samplesize = ft->info.size;
break;
case SF_FLOAT:
ft->info.size = ST_SIZE_DWORD;
ft->info.encoding = ST_ENCODING_FLOAT;
samplesize = sizeof(float);
break;
default:
st_fail("Soundfile input: unknown format 0x%x",
sf->info.sf_packmode);
return(ST_EOF);
}
ft->info.channels = (int) sf->info.sf_chans;
if (ft->info.channels == 0)
ft->info.channels = 1;
/* Read codes and print as comments. */
readcodes(ft, &sfhead);
/* Needed for rawread() */
rc = st_rawstartread(ft);
/* Need length for seeking */
if(ft->seekable){
ft->length = st_filelength(ft)/samplesize;
sf->dataStart = st_tell(ft);
} else {
ft->length = 0;
}
return(rc);
}
static int st_sfstartwrite(ft_t ft)
{
sf_t sf = (sf_t) ft->priv;
SFHEADER sfhead;
SFCODE *sfcodep;
char *sfcharp;
int rc;
/* Needed for rawwrite() */
rc = st_rawstartwrite(ft);
if (rc)
return rc;
sf->info.magic_union._magic_bytes.sf_magic1 = SF_MAGIC1;
sf->info.magic_union._magic_bytes.sf_magic2 = SF_MAGIC2;
sf->info.magic_union._magic_bytes.sf_param = 0;
/* This file handler can handle both big and little endian data */
if (ST_IS_LITTLEENDIAN)
sf->info.magic_union._magic_bytes.sf_machine = SF_VAX;
else
sf->info.magic_union._magic_bytes.sf_machine = SF_SUN;
sf->info.sf_srate = ft->info.rate;
if (ft->info.size == ST_SIZE_DWORD &&
ft->info.encoding == ST_ENCODING_FLOAT) {
sf->info.sf_packmode = SF_FLOAT;
} else {
sf->info.sf_packmode = SF_SHORT;
/* Default to signed words */
ft->info.size = ST_SIZE_WORD;
ft->info.encoding = ST_ENCODING_SIGN2;
}
sf->info.sf_chans = ft->info.channels;
/* Clean out structure so unused areas will remain constain */
/* between different coverts and not rely on memory contents */
memset (&sfhead, 0, sizeof(SFHEADER));
memcpy(&sfhead.sfinfo, &sf->info, sizeof(struct sfinfo));
sfcodep = (SFCODE *) &sfcodes(&sfhead);
sfcodep->code = SF_COMMENT;
sfcodep->bsize = strlen(ft->comment) + sizeof(SFCODE);
while (sfcodep->bsize % 4)
sfcodep->bsize++;
sfcharp = (char *) sfcodep;
strcpy(sfcharp + sizeof(SFCODE), ft->comment);
sfcodep = (SFCODE *) (sfcharp + sfcodep->bsize);
sfcodep->code = SF_END;
sfcodep->bsize = sizeof(SFCODE);
sfcharp = (char *) sfcodep + sizeof(SFCODE);
while(sfcharp < (char *) &sfhead + SIZEOF_HEADER)
*sfcharp++ = '\0';
st_writebuf(ft, &sfhead, 1, sizeof(SFHEADER));
return(ST_SUCCESS);
}
/* Read and write are supplied by raw.c */
/* IRCAM Sound File */
static const char *sfnames[] = {
"sf",
NULL
};
static st_format_t st_sf_format = {
sfnames,
NULL,
ST_FILE_STEREO | ST_FILE_SEEK,
st_sfstartread,
st_rawread,
st_rawstopread,
st_sfstartwrite,
st_rawwrite,
st_rawstopwrite,
st_sfseek
};
const st_format_t *st_sf_format_fn(void)
{
return &st_sf_format;
}